netfilter: xt_CT: allow to attach timeout policy + glue code

This patch allows you to attach the timeout policy via the
CT target, it adds a new revision of the target to ensure
backward compatibility. Moreover, it also contains the glue
code to stick the timeout object defined via nfnetlink_cttimeout
to the given flow.

Example usage (it requires installing the nfct tool and
libnetfilter_cttimeout):

1) create the timeout policy:

 nfct timeout add tcp-policy0 inet tcp \
	established 1000 close 10 time_wait 10 last_ack 10

2) attach the timeout policy to the packet:

 iptables -I PREROUTING -t raw -p tcp -j CT --timeout tcp-policy0

You have to install the following user-space software:

a) libnetfilter_cttimeout:
   git://git.netfilter.org/libnetfilter_cttimeout

b) nfct:
   git://git.netfilter.org/nfct

You also have to get iptables with -j CT --timeout support.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/include/linux/netfilter/xt_CT.h b/include/linux/netfilter/xt_CT.h
index b56e76811c04..a064b8af360c 100644
--- a/include/linux/netfilter/xt_CT.h
+++ b/include/linux/netfilter/xt_CT.h
@@ -16,4 +16,16 @@ struct xt_ct_target_info {
 	struct nf_conn	*ct __attribute__((aligned(8)));
 };
 
+struct xt_ct_target_info_v1 {
+	__u16 flags;
+	__u16 zone;
+	__u32 ct_events;
+	__u32 exp_events;
+	char helper[16];
+	char timeout[32];
+
+	/* Used internally by the kernel */
+	struct nf_conn	*ct __attribute__((aligned(8)));
+};
+
 #endif /* _XT_CT_H */